- making oscimap default backend

- added about-screen
- added TreeTile for Tile lookup, dropping that HashMap
- using simple line-shader instead of std-derivatives one,
  about twice as faster here
- use distance calculation from MapRenderer - removing TileScheduler
- no need for MapGeneratorJob, pass MapTile directly to MapWorkers
- added two-finger tap gestures for zoom-in/out
- added tub/tron rendertheme
- started caching for oscimap
- add x/y coordinates to MapPosition, using it in MapRenderer
- create tag hash when needed
- no need for long tile coordinates max zoomlevel 31 should suffice

res/values/styles.xml

@@ -3,7 +3,6 @@
 
     <style name="MyActionBar" parent="android:style/Widget.Holo.Light.ActionBar">
         <item name="android:background">@drawable/action_bar</item>
-        <item name="android:windowActionBarOverlay">true</item>
     </style>
 
     <style name="Theme.TileMap" parent="android:style/Theme.Holo">